Fixed Ladder Installation – the process from start to finish

A customer called asking for a safe and secure means of accessing their roof and us to do a fixed ladder installation. They have a building that has multiple tenants and didn’t want to have to go through the tenants’ space every time roof access was needed, so an interior ladder and roof hatch combination was off the table. This happens more often than not either because they don’t have a good location inside to mount the ladder or they don’t want to make a hole in their roof.

We went out for a preliminary site visit to verify what the job would entail. The location that was chosen to mount that ladder at was flat from floor to roof. There were no gutters so we would not have to worry about having to either start and stop the gutter and add another down spout, or add a step across platform at the top of the ladder to keep within OSHA’s requirement of a maximum step across a distance of 12”.

Installation site for caged ladder

Installation site for caged ladder

There was a slight parapet at the top of the wall so we set up the extension ladders to verify that the parapet was under 14”high so we would not need to have a crossover ladder with return on the back. We did elect to modify the walk through handrail to remove the return down to the roof to allow more flexibility with installation. Using the self supported walk through handrail allowed a proper fit regardless of the parapet thickness.

Materials were fabricated and shipped to the jobsite where the installation crew attached the lower and upper ladder sections together with the supplied brackets. Next, the ladder was hooked up and elevated into place by a forklift boom. By securing the ladder a little lower than the top, but well past the weight ½ way point, we were able to safely use a shorter, readily available lift and avoid the added cost of additional machine rental.

Lifting the fixed ladder into position

Lifting the fixed ladder into position

The ladder was also outfitted with the LG6 6’ security ladder rung guard to prevent unauthorized access to the ladder. Once hoisted into place, ½” sleeve anchors were inserted into holes drilled into the block and turned until expanded properly, securing the ladder to the wall. For this ladder 18 anchors were used, distributing the 650# ladder and 300# capacity load to well below the tension and shear values for sleeve anchors with the recommended 1-7/8” minimum embedment and a 4:1 (25%) safety factor. Installation was completed in just one morning by a crew of two.

Completed installation of fixed ladder

Completed fixed ladder installation

Installation of the Mezzanine’s IBC Stairs

 

Finished L-shaped external IBC stair

Installed external IBC staircase

Previously, I had written a blog post briefly discussing how to put one of our mezzanines together. It had a lot of good photos taken during the installation, so I was able to go through section by section what was done.  There was one particular area I didn’t get to to over in much detail though; the stairs.  While with the previous system that I wrote about, the customer designed and fabricated their own staircase, I recently received a fantastic series of photos from the installation of another system; this time with partially installed stairs included.

installing the IBC stair

Setting up the stairs

The IBC stairs for or mezzanine systems ship in knock down form and need to be installed in the field.  When installing them, you’ll want to lay the stringers on the floor about 3’ apart with the closed face of the stringers inward.  The diamond tread stair treads consist of a closed back riser and stair tread weldment.  Starting with the top tread and riser, you’ll need to bolt the the tread to the stringer fastening it on the inside of the tread.  Only hand tighten the bolts at this time, then work your way down positioning the riser of the next tread behind the flat weldment of the nose on the tread above.  After all the treads have been attached to the stringers (hand snug) you’ll need to install the bottom riser using self tapping screws.  You’ll then need to hoist the stairs up to the mezzanine deck.  Making sure that the dimension from the top of the deck to the top tread is equal to the dimension between the other treads, you’ll need to field drill the the attachment holes using a 9/16” drill and attach it to the mezzanine system.  You’ll also need to install the top tread plate on top of the mezzanine deck closing off the riser from your first tread.  From the underside, you’ll need to tighten up all the bolts and attach the risers to the back of the above tread’s nose via a couple self tapping screws.  Afterwards you’ll need to anchor the stairs to the ground.

 

Now all that’s left is to finish off the handrail.  The hoops that form the 21” and 36” handrails and handrail extensions come already welded to the stringers.  On each of the uprights, you’ll need to attach an elbow assembly via self tapping screws.  This will provide you with the saddles to support the outer 42” handrail.  You’ll need to take a piece of guardrail pipe for each side, and lay them flush against the saddles, fixing them in place with self tapping screws once again.  As the top line of rail will be longer than the stair run, you’ll want to drop a plumb line from the bottom edge of the rail to the edge of the mezzanine deck and again to the front edge of the bottom stair tread, cutting the pipe square.  Finally, you’ll need to install a plastic plug cap in the openings of the top rail to finish it off.  

Mezzanine Supported Modular Office

Mezzanine with modular office above

Mezzanine supported modular office with a two-wall modular building below

Whether you’re running out of room on the plant floor or need to oversee production, mezzanines are commonly employed to support and elevate modular buildings.  Recently we received some great photos back on a project we completed last month for a mezzanine supported modular office that I thought you might like to see.  The customer was located right here in Northeast Ohio.  They were putting in a new line on the plant floor and needed to tear down some offices they had in order to make room.   There wasn’t enough space to relocate the offices elsewhere on the plant floor, so they decided to utilize some of their unused overhead space.

Side view of mezzanine and modular office.

A 9’ high mezzanine supported modular office with an 8’ high modular wall system below.

When thinking on putting in a mezzanine supported modular building, it’s important to consider just how much space is available.  Remember that with typical column spans in low seismic areas, you’ll probably lose 1’3” to 1’5” for the mezzanine itself.  If you plan on having people move through the area you will need to maintain a minimum of 7’ for clearance.  The modular building panels are typically 8’ or 9’ tall, and unless you are planning on supporting them by the structure above, you will probably want about a foot more in order to install the roof deck to the panels which helps form the membrane that holds the system together.   In this particular case the customer’s mezzanine had a clearance height of 8’7” with a 9’10” top of deck.  This provided us enough room to install a modular office above (9’ tall panels, 9’3-1/8” overall height, 8’6” clearance height) and an 8’ high (8’3-1/8” overall with a 7’6” clear ceiling height) modular wall system below.

inside modular building

Four wall modular office above the mezzanine with customer provided/ installed floor covering

While designing these mezzanine supported modular offices, we’re often asked if we can utilize the adjacent existing walls.  While this is commonly done on the main floor of a facility, unfortunately we cannot do this up on top of the mezzanine deck.   There will always be some movement and vibrations on top of an elevated structure and because of this the structure would need to be a four wall system and not tie into the adjacent walls.  In this particular care, we put in a four wall system above the mezzanine deck as well as a two wall system below the deck to create an enclosed pass way between the production floor, the front offices beyond the cinder block wall, and the production floor entrance way to the outside.

inside view of two wall modular wall system

Two wall modular wall system below the mezzanine

It took our installers 6 work days to unload and install (both mechanical and electrical) the 24’x10’ mezzanine, the 24’x10’ 4-wall modular office above, and the 9’x22’9” two wall modular wall system below, and we had yet another very happy customer.

Now Available, The SafeMezz360 Mezzanine Safety Gate

closed SafeMezz360 mezzanine safety gate

The new SafeMezz360 mezzanine safety gate

It’s an exciting time over in our mezzanine gate division.  Over the next year we will be introducing several new gates to our product line.  Today, I have the pleasure of introducing the first new gate to our regular product line up; the SafeMezz 360 mezzanine safety gate.

Open mezzanine safety gate

The SafeMezz360 mezzanine safety gate open to the edge.

Lately many facilities are opting to follow the voluntary ANSI standards in their workplace.   One area in which ANSI goes above and beyond OSHA would be ANSI MH28.3 Section 6.4.3 requirement that states: “A work platform shall be designed such that the elevated surface is protected by the guards at all times. Gates that swing open, slide open or lift out, leaving an unprotected opening in the guarding, are not acceptable.”   This means that at facilities following the ANSI standards, all pallet openings need to be protected by a true double layered safety gate so that your employees always have a line of guard rail between them and the edge of your deck.

In order to meet these more stringent ANSI requirements, the SafeMezz360 gate utilizes two counter balanced gates which travel on a track up and over your pallets.  Each gate consists of the ANSI required 42” top rail, 21” mid rail, and 4” kick plate. Designed for repetitive use in tough work environments, the SafeMezz 360 is constructed from heavy gauge steel with a durable safety yellow powder coat finish and utilizes an industrial duty chain and sprocket operating system.  The SafeMezz 360 mezzanine safety gate also features a slam proof cushioned dampening system to keep the gate from dropping on your toes.

The SafeMezz 360 is easy to install and operate.  The gates travel smoothly on 2” nylon rollers along it’s track system providing for an easy one-handed operation.  The gate ships in knocked down form for a simple assembly in the field, and bolts easily into place on the mezzanine.

In order to minimize the lead times, we have single and double wide openings available as “quick ship” mezzanine safety gates.  This means that many of the components will be prefabricated and stocked at the factory so that your gate should be ready to ship out in 1-2 weeks. Custom sized safety gates will still be available, but will need to go through full production (typically around 6 seeks after signed approval drawings).

Replace stairs in tight fit locations and meet code

Many locations have old stairs that need to fixed or replaced due to age, damage etc. Generally speaking regardless of the code in place when the original stair was made, you will need to update your stair to the current building code (IBC) when you replace stairs.

OSHA staircase, replace stairs

Stair meeting OSHA standards

3404.1 General. Except as provided by Section 3401.4 or this section, alterations to any building or structure shall comply with the requirements of the code for new construction. Alterations shall be such that the existing building or structure is no less complying with the provisions of this code than the existing building or structure was prior to the alteration.

This becomes an issue when stairs are installed in tight locations under codes that vary greatly from today’s current International Building Code (IBC) variants.

Imagine having a 12’ high stair in place with a riser height of 9” and a tread depth of 9”. This stair would have (16) treads, 9”deep for a total run of 11’3”.

If the replacement stairs would be required to meet IBC code (adopted by all of the states) they would now need to have (20) treads, 11” deep for a total run of 18’4”. The IBC stairs would extend 7’1” further than the originally installed stairs.

The increased run and decreased slope can wreak havoc on your facilities if the original stairs stopped right before a hallway (new stairs would extend well into the hallway) or if the stairs are enclosed (new slope would cause head clearance issues with existing structure).

If the above situation applies to you don’t sweat it. The above referenced IBC code section does have an exception that may help

Exceptions:

  1. An existing stairway shall not be required to comply with the requirements of Section 1009 where the existing space and construction does not allow a reduction in pitch or slope.
  2. Handrails otherwise required to comply with Section 1009.12 shall not be required to comply with the requirements of Section 1012.6 regarding full extension of the handrails where such extensions would be hazardous due to plan configuration.

 

Why the exemption for stairs (and possibly ramps, though not specifically called out)? The thinking behind the exemption is that without it, stairs that need to be replaced and are not safe will be neglected and not maintained due to the inability to bring them up to current codes. It is better to have a well maintained stair meeting an earlier code than have a poorly maintained stair that doesn’t meet current codes.

Removable Access Panel in a Modular Building Equipment Enclosure

cmm room equipment enclosure

New CMM room with removable panel above the door

A very common application for modular buildings is as an equipment enclosure.  The customer is trying to cordon off an area on their production floor to encapsulate a certain process.   Sometimes they are trying to isolate the sound it produces.  Sometimes they are trying to isolate it from a dusty environment.  A lot of these machines, such as CMM machines, won’t fit through a 6’8” or 7’ high doorway.  Once the equipment is in place it usually stays there for many years, but customers often want the ability to get it in and out of the room on rare occasions should the need arise without having to disassemble a good chunk of the building.  For a doorway that will only be used once in a blue moon, it’s rarely cost effective to order a custom swing door, or put in an additional canister style door for equipment access.  A much more cost effective method that we’ve found is to put in a removable access panel.

Removable panel on a modular building

Removable panel above a 6′ x 8′ doorway

Recently, we provided a customer with a modular building to use as an equipment enclosure for their new CMM equipment.  On a day to day basis, a 6’ wide x 6’8” high double door would be more than sufficient for them, but they wanted to be able to occasionally pass something larger through the doorway.   If they were going to pass taller materials through the door way more regularly we could have ordered in a special 8’ high double door, but because they only needed once in a blue moon access we were able save them several hundred dollars in material by putting in a removable panel section above their doorway.  

removable panel drawing

Adding a removable panel is a fairly simple thing to do.  The panels were cut in the factory to accommodate a 6’ wide x 8’ high opening.  We took an additional panel section to cover the gap above the 6’ x 6’8” door and framed it in using the channel for the door frame and some additional “h” cap trim pieces we normally use along the top of the panels.  We also installed “h” cap to the building panels at the opening above the door and fastened the removable panel to the opening.  This sealed off the seams between the panels.  Now when the customer needs that little bit of extra space, all they need to do is remove the screws connecting the panel to the building, allowing them to fit their larger equipment through.

 

 

 

Visiting an Old Mezzanine Supported Modular Office

mezzainine supported modular office from 1997

After almost 20 years of service this modular office is holding up great

Occasionally, I’m asked about how well our modular offices hold up over the years if they are designed so that they can be reconfigured in the future as your needs change.  Surely, after general wear and tear they will want to just order a new building anyway, no?   Well, I recently had the opportunity to visit an old customer of ours.  Over the years, we’ve provided them with a number of mezzanines, catwalks, and modular offices.  Several of the modular offices have been disassembled, modified, and reinstalled in different locations.  While there, I got an opportunity to look at this old tank platform mezzanine and A-wall 300 modular office we provided them with back in 1997.  The steel decking has started to bend up a little at the seam in a couple areas, but after almost twenty years of service the mezzanine and modular office were in excellent condition.  If the customer wanted to, it would still be a simple task to disassemble the modular office and put it up again in a new location, possibly with a few modifications.  The components are all still compatible with what we provide today.  The only design change is that the I-splines used to connect the panels in the A-wall 300 modular building system are now typically painted to match the panels as opposed to the same color as the framing on the windows and doors.  So yes, these modular buildings are built to last.

 

Steel Fixed Ladder Handrail Options

Does my ladder need a handrail?

Almost all ladders will have an extension at the top, with the only exceptions being ladders accessing roof hatches, manholes, floor doors, or anything else that closes over the top of the ladder. If you are exiting the ladder to the side or going to an offset platform due to the 30’ maximum climbing distance between ladders, you will need to add four more rungs above the platform. Those rungs are only to be used for hand-hold only, to give you something to grab onto to safely exit the ladder.

 

Side step ladder platform for climbs over 30' in length

Side step ladder platform for climbs over 30′ in length

If the ladder is going up to a wall, to a roof, or to a mezzanine, then you will need extensions on the ladder for the “walk-through” exit of the ladder.

We have three different designs of walk-through handrails and I’ll go into the details on each of them below.

Steel ladder handrail options

Steel ladder handrail options

The first design, the “8” shape, is our standard ladder design. This is the most commonly used handrail setup as it allows for the top of the walk-through to mount to the landing surface, providing the greatest rigidity at the handrail. It also makes installation easy, as there are no questions where the top rung mounts; it is always installed properly meeting the top of the landing surface as required by code.

In cases of short parapets or locations where you cannot have the walk-through handrail anchor to or even set upon the roof you would use the second “P” profile, our “self supported walk-through handrail”. This handrail design works well when there is a parapet under 14” high that the handrail mounting pads would not line up with. It is not a necessity to use the “P” shaped handrail in those instances. Many installers still prefer the “8” layout for the added cross brace back to the ladder. When installing a ladder with our self-supported walk-through handrail, be sure to install properly, with the top rung level with the top of your roof. There is no foot pad at the top to ensure this is done, so installation just requires a check to be sure of compliance.

The last ladder handrail design is our “customer supplied walk-through handrail”. This is used in instances where the installation location has existing railing and handrails that they want to weld the walk-through handrail to. This is useful in locations where space is minimal and existing site conditions allow for field welding to existing rails.

Not shown is our step across platform, which is essentially a crossover used when site conditions require the ladder rung to be more than 12” away from the landing surface as required by OSHA standards. Most commonly, this is used on locations with gutters that are more than 5” off the face of the climbing side of the wall.

OSHA 1910.27(d)(3)

“Ladder extensions.” The side rails of through or side-step ladder extensions shall extend 3 1/2 feet above parapets and landings. For through ladder extensions, the rungs shall be omitted from the extension and shall have not less than 18 nor more than 24 inches clearance between rails. For side-step or offset fixed ladder sections, at landings, the side rails and rungs shall be carried to the next regular rung beyond or above the 3 1/2 feet minimum (fig. D-10).

Putting a Window and a Through the Wall Air Conditioner in the Same Panel of a Modular Building

Non progressive modular building system with a through the wall HVAC

The existing modular building with a through the wall HVAC, before modifications.

 

Modular building systems are designed to be relatively easy to modify should the need arise.  This past summer we put in this 10′ by 11′ odd shaped modular building to serve as a control booth at a steel plant here in Ohio.  All the panels had a window in them, aside from a small panel on the end which held a through the wall heat/cool air conditioner. After everything was installed, the workers who operate the control booth determined that they wanted to add a window to that panel as well, and move the air conditioner above the window.  Unfortunately, modular wall panels are not generally designed to support a through the wall air conditioner when placed above a window.   We could, however, modify it to put the air conditioner below the window.

non progressive modular wall system dissassembly

Removing the modular building wall panel to make the modifications

Depending on the modular building system used, there are a couple of different ways to go about making the modifications.  In this particular case, with it being a non-progressive modular building system with steel skinned panels, we reused the existing materials, and made the modification directly to the panel.  We shipped the customer a new custom width window to fit inside the narrow panel, and some new trim for the framed HVAC opening as the customer decided to put in a heavier duty air conditioner while we were doing the modifications.  All the other components were reused from the existing.

Modular wall system with window and HVAC in the same panel

After the modifications the wall panel now has a new window and HVAC below

 

The modifications were fairly quick and easy.  When the installers arrived, they disassembled that section of the building to remove the panel in question.  They then cut the modular building panel to fit the new window and air conditioner.  Afterwards, it was simply a case of putting it back together.  All said and done, it took two guys about half a day to complete the modifications.

 

Minimizing the Thickness of a Mezzanine Deck

W16x31 primary framing member with 4”x14” long tab side mounted to the column

A mezzanine deck thickness between the bottom of the primary framing member and the top of deck.

 

There are many times when the thickness of a mezzanine needs to be minimized due to various height restrictions.  The tightest we could normally provide a storage mezzanine would be one foot between the clearance height underneath and the top of deck.  In order to do this though, there are several things we need to consider.

First, we need to consider where the mezzanine is going.  Mezzanines in highly seismic regions, such as the Pacific coast, typically require larger and heavier beams than those installed in regions with minimal seismic activity, such as here in northeastern Ohio.  This doesn’t necessarily mean that we won’t be able to get the deck thickness down to a foot, but it does make it more difficult.

Next, we’ll want to look at our general design and column layout.  The positioning of the columns can greatly affect the size of the beams required and, in turn, the thickness of the mezzanine.  What are the required column spans for the project?  Typically we like to keep our column spans under 20 feet on center for economic concerns.  Longer spans require bigger beams.  Often if we’re trying to minimize the deck thickness we might need to go with even shorter spans.  We’ll also want to avoid a cantilevered deck if possible, as that too can require a larger beam than normal.

Another thing to consider is bracing on the deck.  Generally we have a moment connection between the columns and our framing members by trimming back the wide flange I-beam and bolting it directly to the side of the column without requiring knee bracing.  While trying to minimize the thickness of the mezzanine, we might ask you if we can use “tabs”.  These are typically 14” long by 4” high pieces of angle that we attach below the primary framing members at the columns.  This is particularly important when trying to keep the thickness of the mezzanine to just a foot, as there just isn’t enough beam to make a good solid connection.  We might be able to provide a mezzanine with 7’ clear and an 8’ top of deck, but at the columns above the baseplates you’ll have a piece of angle coming 4” off of that 7’.

The final thing to consider is price.  Minimizing the thickness of the mezzanine will increase the price.  The beams might be smaller, but they are heavier.  We might need to use more columns than usual.  We might have to replace all “C” section secondary framing members with structural steel beams.  All this extra steel adds to the cost.  On average, most of the mezzanines we provide have a deck thickness of 1’3” or 1’5”.  If the extra couple inches are critical then by all means go for it, but if not, it is usually not worth the added cost.